Heretofore, in the assembling of a ball type constant velocity joint, as described in FIG. 5 of JP2000-154833 A (Patent Document 1), it is done to assemble an inner race inside a cage. Specifically, in the state that the axial direction of the inner race and the axial direction of the cage are set to be almost orthogonal, one of groove wall protrusions (inner race peripheral protrusions) which are configured by sidewall surfaces of adjoining inner race ball grooves is inserted into a widow portion of the cage. In this state, the whole of the inner race is made to come inside the cage by pivoting the inner race relative to the cage about the axis of the inner race. Thereafter, the axial direction of the inner race and the axial direction of the cage are aligned, whereby the assembling of the inner race and the cage is completed.
In order to insert the groove wall protrusion (inner race peripheral protrusion) of the inner race into the window portion of the cage in this assembling, the inner race is formed at one axial end on the peripheral side with cutouts directed radially inward (refer to FIG. 1 of Patent Document 1). This makes the groove wall protrusions of the inner race narrow in axial length, so that the insertion into the window portion becomes possible.